vendor : update cpp-httplib to 0.45.0

[cabelo]

Overview

Additional information

Requirements

• I have read and agree with the contributing guidelines
• AI usage disclosure: NO

What's Changed

v0.45.0

Bug fixes

• Fix crash on empty / comma-only X-Forwarded-For when set_trusted_proxies() is configured. get_client_ip() previously called front() on a vector that was empty whenever the header tokenized to zero segments ("", ",", ", , ,"); it now returns an empty string so process_request() falls back to the connection-level remote address instead of crashing
• Fix keep-alive corruption on requests without a framed body. The post-response drain ran for any request that expect_content() accepted, so a method like DELETE /items/1 with no Content-Length and no Transfer-Encoding would, on a persistent connection, let read_content consume bytes belonging to the next pipelined request — making the second request appear to vanish. The drain now only runs when the request actually has a framed body (Content-Length or chunked). The non-SSL "stray-bytes → 413" payload-limit check is likewise limited to non-persistent connections, since on keep-alive any pending bytes may be the next request rather than an unframed body

Internal

• Extract detail::has_framed_body() and detail::is_connection_persistent() helpers used by the keep-alive fix above Bug fixes